The present invention relates to an electrical connector. More specifically, the present invention relates to an electrical connector having a terminal formed of a metal plate bent in a thickness direction thereof and capable of elastic deformation in the thickness direction. In the electrical connector, the terminal is held with a terminal holding wall of a housing.
A conventional electrical connector (a connector) includes a terminal mounted into a terminal holding wall from a side that the connector receives a mating connector. When the connector is connected to the mating connector, the terminal contacts a mating terminal of the mating connector. Further, the terminal deforms elastically pressed by the mating terminal. Thus, with a contact pressure, the terminal maintains a connecting state thereof with respect to the mating terminal. When the mating connector is disconnected, a frictional resistance is generated at a contacting portion of the terminal and the mating terminal. As a result, the terminal may come off from the terminal holding wall by a force toward an extracting direction of the mating connector generated by the frictional resistance.
Patent Reference has disclosed a conventional electrical connector. The conventional electrical connector (connector) disclosed in Patent Reference includes engaging surfaces on both of a terminal and a housing thereof at respective step portions. When a mating connector is extracted, a pair of the engaging surfaces contacts to each other in a connecting direction of the connector and the mating connector (connectors) and regulates a deformation of the terminal toward the connecting direction of the connectors, so that the terminal can be prevented from coming off.
Patent Reference: Japanese Patent Publication No. 2007-134091
In the conventional electrical connector, the housing with a rectangular solid shape includes a receptacle recess portion formed by a circumferential wall of the housing for receiving the mating connector. Further, a plurality of holding grooves for holding the terminals is formed in a sidewall with a regular interval therebetween in a longitudinal direction of the housing.
The terminal is formed of a metal plate having a belt shape and bent in a thickness direction thereof to form a laterally facing S-shape. The terminal includes a contact arm portion at one free end thereof. The contact arm portion includes a contact portion for contacting with the mating terminal, and is capable of elastic deformation. The terminal further includes a held portion at the other free end thereof held by the housing.
The terminal is inserted into the holding groove from a forefront of the held portion first in a receiving direction of the mating connector, while maintaining the laterally facing S-shape. The terminal is held by an inner surface of the holding groove. The contact arm portion held into the holding groove extends in an upward direction, and the contact portion thereof protrudes toward the receptacle recess portion from the holding groove.
The contact arm portion of the terminal includes an engaging protrusion at a portion thereof held in the holding groove, and the engaging protrusion protrudes in a width direction of the terminal. An upper surface or an engaging surface of the engaging protrusion extends in a direction perpendicular to the connecting direction of the connectors. An area of the engaging surface is determined by a size of the engaging protrusion in the width direction and the thickness direction of the terminal.
Corresponding to the engaging protrusion, the housing includes a regulating step portion in the inner surface of the holding groove. The regulating step portion protrudes from the inner surface of the holding groove, and is situated at a position at an upper side of the engaging protrusion and an inner side of the holding groove. The regulating step portion includes a lower surface extending perpendicular to the connecting direction of the connectors for contacting and engaging with the upper surface of the engaging protrusion when the mating connector is extracted.
When the connector is connected to the mating connector, the contact arm portion of the terminal deforms elastically toward the holding groove due to a contact pressure from the contact portions of the connector and the mating connector. Accordingly, a portion of the upper surface of the engaging protrusion is situated at a position facing the lower surface of the regulating step portion, that is, right under the regulating step portion.
When the mating connector is extracted, the terminal deforms in the upward direction by an upward force in the extracting direction of the mating connector due to a frictional resistance between the respective contact portions of the terminal and the mating terminal. As the terminal deforms upward, the upper surface of the engaging protrusion engages with the lower surface of the regulating step portion. As a result, the upper surface of the engaging protrusion contacts and engages with the lower surface of the regulating step portion.
In the connector disclosed in Patent Reference, as described above, the engaging protrusion of the terminal engages with the regulating step portion of the housing in the extracting direction of the mating connector, thereby regulating an excessive deformation of the terminal and preventing the terminal from coming off.
In the conventional connector described above, the upper surface of the engaging protrusion engages with the regulating step portion of the housing when the mating connector is extracted. The upper surface can have as little size as the thickness of the engaging protrusion at a maximum in the thickness direction of the terminal, though the size is decisive for the area thereof. As a result, when a manufacturing error or an assembling error occurs, the engaging protrusion may not reach the position right under the regulating step portion when the terminal deforms elastically as the connector is connected to the mating connector. In this case, the terminal may come off due to a failure to engage the engaging protrusion with the regulating step portion in the connecting direction of the connectors.
Further, as described above, the lower surface of the regulating step portion engaging with the upper surface of the engaging protrusion is perpendicular to the connecting direction of the connectors. In order to form the lower surface, it is necessary to open a hole penetrating a bottom wall portion of the housing for removing a mold from a bottom of the housing after the housing is shaped. As a result, the bottom wall portion may not obtain a sufficient strength. Furthermore, when the connector is mounted on a circuit board, an electrical conduction therebetween may occur due to a narrow space. Consequently, an electric property may be deteriorated.
In view of the problems described above, an object of the present invention is to provide a connector capable of securely preventing a terminal from coming off as a mating connector is extracted, and not including a hole at a bottom wall portion thereof.
Further objects and advantages of the invention will be apparent from the following description of the invention.